Tsunami Evacuation Complex: Terrasse Orange Toi | Imai Laboratory, IIS, U Tokyo + Nippon Koei Urban Space - Arch2O. com

The Terrasse Orange Toi project, located in Toi, Izu City, stands out as Japan's pioneering building that fully integrates tsunami disaster prevention with tourism. Toi, a traditional hot spring town famed for its scenic pine groves and rich Japanese landscape, faces a serious threat from a potential 10-meter tsunami that could strike within six minutes following a Nankai megathrust earthquake. Unlike many coastal regions that opt for large seawalls, the local community chose a different approach to preserve the natural beauty of Suruga Bay. They designated Toi as Japan’s only Tsunami Disaster Special Caution Zone and decided to rely on tsunami evacuation towers instead of bulky protective barriers. This community-driven decision led to the creation of a multi-functional tower serving both as an evacuation refuge in emergencies and as a vibrant tourist attraction. Positioned at the boundary of the coastline and Matsubara Park’s iconic pine groves, the tower is designed to symbolize a gateway between the sea and the town. Careful architectural planning ensured the building integrated with its natural surroundings. Using 3D scans of the bent pine trees, designers avoided cutting large-diameter pines, shaping the building layout to coexist harmoniously with these natural elements. The tower’s evacuation and observation floors are elevated 14 meters above ground, safely above the reach of tsunamis. Below, a spacious piloti area creates shaded shelter akin to the natural pine groves for beach visitors, doubling as an intermediate evacuation zone accessible from the beach via a large staircase. The transparent glass enclosure of the upper floors supports tourism functions while allowing visitors to enjoy panoramic views. Structural support comes from slender Vierendeel-girder columns, maintaining openness. Two external staircases wrapping the building help tourists unfamiliar with the area find evacuation routes easily while offering scenic walks through Matsubara Park’s natural beauty. Reflective materials play a subtle yet crucial role in blending the tower into its surroundings. Surfaces like the underside of the piloti mirror the pines, sea, and sunset, minimizing visual impact and enhancing harmony with the environment. Architecturally, the tower acts as a symbolic gateway where nature and human design intersect, preserving the coastal views and fostering a new landscape that respects both. The project was developed by the Imai Laboratory at the University of Tokyo’s IIS in collaboration with Nippon Koei Urban Space. Structural engineering was handled by Nagata Structural Engineers, with electrical and mechanical engineering support from EOS plus and Kawamura Engineering Consultants, respectively. Construction was carried out by Tsuchiya Kensetsu and Aoki Kogyo. The design team, led by Kotaro Imai and Kan Kunieda, focused on sustainability and community integration. Signage was designed by Maruyama Design, contributing to the building’s user-friendly navigation. By merging disaster preparedness with everyday use and tourism, the tower encourages continuous community engagement and disaster training. This model not only strengthens local resilience but also revitalizes the region by attracting visitors year-round. The Terrasse Orange Toi demonstrates how thoughtful architectural design can address critical safety needs while enhancing cultural and environmental values, creating a blueprint for coastal towns facing similar risks.